JP4130541B2 - Optical recording medium on which wobble signal carrying header information is recorded, wobble signal recording apparatus, recording method, reproducing apparatus, and reproducing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical recording medium, and more particularly to an optical recording medium having a wobble track on which a wobble signal is recorded, a wobble signal recording method, a recording apparatus, a wobble signal reproducing method, and a reproducing apparatus.
[0002]
[Prior art]
  A concentric or spiral track (groove track or land track) is formed on a recordable optical disk such as a DVD-RAM. A wobble signal is recorded on the track using a change in the amplitude direction. A track on which a wobble signal is recorded is called a wobble track. The wobble signal is one of means for recording an auxiliary clock signal for obtaining synchronization information during recording / reproduction. The wobble signal has a frequency in a band that does not affect the tracking server mechanism provided in the recording / reproducing apparatus and is used as an auxiliary clock signal that assists the system clock. The DVD-RAM standard (DVD Specifications for Rewritable Disc Version 2.0) is in the radial direction.Track kingThe wobbling signal frequency is specified to be about 157 KHz at the standard linear velocity.
[0003]
User data is recorded on the wobble track by a pickup device. In order to record user data through the laser beam, a pickup device provided in the recording apparatus and oscillating the recording laser must be able to move to a desired position. Therefore, addressing information for moving the pickup device to a desired position is recorded on the optical disc. Here, “addressing information” refers to “identification information given to each unit recording block when an information track is divided into a plurality of unit recording blocks”.
[0004]
  Conventionally, a typical method for recording addressing information on an optical disc is to form a header information area separately from a track on which user data is recorded, and record the addressing information there.Is the way.
[0005]
FIG. 1 is a schematic view of a conventional optical disc.
[0006]
  Referring to FIG. 1, a user data area track (land track and / or groove track) is formed on an optical disc.Header information areaIs provided separately from the track. The header information area is arranged in a predetermined area of the sector (unit recording block), and the pickup device provided in the recording / reproducing apparatus can easily move to a desired position through the addressing information recorded in the header information area. As a result, the sector number, sector type, information track, etc. recorded in the header information area can be recognized.The servoControl is also possible.
[0007]
The header information recording system according to the 1999 DVD RAM standard version 2.0 is a CAPA (Complementary Allocated Pit Address) system. As shown in FIG. 1, the CAPA method records four header information in one sector. However, two sets of two header information are separated from the center of the information track by ½ track to the left and right. This is a recording method.
[0008]
However, providing a separate header information area not only complicates the optical disc manufacturing process, but also the wobbling signal cannot be obtained correctly while the pickup device passes through the header information area, so that an additional compensation is provided. A circuit is required. Furthermore, as the use of multimedia contents becomes universal, when the demand for high-density recording media is increasing, providing a separate header information area results in a reduction in the area where user data can be recorded.
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide an optical recording medium capable of recording more user data, a wobble signal recording method, a recording apparatus, a wobble signal reproducing method, and a reproducing apparatus.
[0010]
Another object of the present invention is to provide an optical recording medium on which a wobble signal from which header information can be extracted and a more stable clock signal can be recorded, a wobble signal recording method, a recording apparatus, a wobble signal reproducing method, and a reproducing apparatus. Is to provide.
[0011]
[Means for Solving the Problems]
The object is to provide a wobble track on which user data is recorded according to the present invention, and the wobble signal recorded on the wobble track is a single frequency signal on which the first header information is edge-modulated. This is achieved by an optical recording medium characterized by the above.
[0012]
  Second header information is phase-modulated and loaded on at least a part of the edge-modulated section of the wobble signal.ing.
[0013]
The first header information includes addressing information.
[0014]
Meanwhile, according to another field of the present invention, an object of the present invention is to provide an edge modulation based on a first signal and a second signal having different edge waveforms at the same frequency in an apparatus for recording a wobble signal on an optical recording medium. A wobble signal generation unit that generates a single frequency wobble signal on which the header information is placed, and a recording unit that records the wobble signal generated by the wobble signal generation unit on the optical recording medium. This can also be achieved by a recording apparatus.
[0015]
The wobble signal generator includes a clock generator that generates a clock signal, a carrier signal generator that generates the first and second signals based on the clock signal, and header information that is input to the clock signal generator based on the clock signal. It is preferable that an edge modulation unit that performs edge modulation using the first and second signals output from the carrier signal generation unit is provided.
[0016]
  The edge modulation unit is for digital data.high levelThe first and second signals are respectively associated with the low level and modulated into analog signals.
[0017]
Further, the object is to perform phase modulation on the first header information edge-modulated based on the first signal and the second signal having different edge waveforms of the same frequency in an apparatus for recording a wobble signal on an optical recording medium. A wobble signal generator for generating a single frequency wobble signal carrying the second header information, and a recording unit for recording the wobble signal generated by the wobble signal generator on the optical recording medium. It is also achieved by the characteristic recording device.
[0018]
The wobble signal generator includes a carrier signal generator that generates the first and second signals, an edge modulator that performs edge modulation on the first header information using the first signal and the second signal, and the second A phase modulation unit that phase-modulates header information using the first signal or the second signal, an edge modulation signal output from the edge modulation unit, and a phase modulation signal output from the phase modulation unit; It is also achieved by a recording apparatus comprising a signal synthesizer that outputs the single frequency wobble signal.
[0019]
Meanwhile, according to another field of the present invention, the object is to provide a wobble signal recording method for recording a wobble signal on an optical recording medium, in which (a) a first signal and a second signal having different edge waveforms of the same frequency. (B) generating a single frequency wobble signal on which header information that has been edge-modulated using the generated first signal and second signal is loaded; and (c) generating the generated single signal. And recording a single-frequency wobble signal.
[0020]
The step (b) preferably includes a step (b1) of generating a clock signal and a step (b2) of performing edge modulation of header information using the first signal and the second signal by the generated clock signal. .
[0021]
  In step (b2), the digital datahigh levelAnd modulating the analog signal with the first and second signals corresponding to the low level, respectively.
[0022]
Further, the object is to provide a wobble signal recording method for recording a wobble signal on an optical recording medium, wherein (a) generating a first signal and a second signal having different edge waveforms of the same frequency, and (b) Generating a single frequency wobble signal carrying the first header information edge-modulated using the first signal and the second signal and the second header information phase-modulated, and (c) It is also achieved by a recording method comprising the step of recording a single frequency wobble signal.
[0023]
(B) includes (b1) generating a clock signal; (b2) performing edge modulation on the first header information using the first signal and the second signal according to the generated clock signal; (B3) phase modulating the second header information using the first signal or the second signal according to the generated clock signal; (b4) the edge modulation signal of the step (b2) and the step (b3) And synthesizing the single frequency wobble signal by superimposing the phase-modulated signal.
[0024]
On the other hand, according to another field of the present invention, the object is as follows: (a) a single signal on which header information that is edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency is placed; A step of reading a frequency wobble signal; (b) generating a duty signal for the read wobble signal; and (c) extracting header information by comparing the generated duty signal. This is also achieved by the header information reproducing method.
[0025]
  Step (b) includes (b1) generating a duty signal for an upper layer level that is a predetermined level larger than the center level of the read wobble signal, and (b2) a predetermined level smaller than the center level of the read wobble signal. Generating a duty signal for the lower levelYeah.
[0026]
  The step (c) includes (c1) generating the binary data by comparing the duty ratios of the duty signals generated in the steps (b1) and (b2), and (c2) the detected binary. A step of extracting the header information from the data;Yeah.
[0027]
Further, the object is as follows: (a) reading a single frequency wobble signal on which header information subjected to edge modulation using the first signal and the second signal having different edge waveforms of the same frequency is loaded; Header information comprising: (a) detecting a level of the read wobble signal at a predetermined phase; and (c) extracting header information by comparing the detected level with a predetermined reference value. It can also be achieved by a regeneration method.
[0028]
The step (c) includes: (c1) generating binary data by comparing the detected level with a predetermined reference value; and (c2) extracting header information by demodulating the generated binary data. It is desirable to provide.
[0029]
On the other hand, the object is as follows: (a) reading a single frequency wobble signal carrying header information that has been edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency; And a header information reproducing method comprising: (c) generating a differential signal for the read wobble signal; and (c) extracting header information based on the generated differential signal. .
[0030]
The step (c) includes (c1) detecting an upper envelope signal of the differential signal, (c2) detecting a lower envelope signal of the differential signal, and (c3) the upper envelope signal and the lower envelope. And extracting the header information based on the signal.
[0031]
  The step (c3) includes (c31)The upper envelope signal and the lower envelope signal;(C32) generating binary data by comparing the level of the obtained difference signal with a predetermined reference value; and (c33) demodulating the generated binary data to obtain header information. It is desirable to provide the step of extracting.
[0032]
Meanwhile, according to another field of the present invention, the object is to perform edge modulation using a first signal and a second signal having different edge waveforms of the same frequency in an apparatus for reproducing header information from a wobble signal. A wobble signal reading unit that reads a single frequency wobble signal on which header information is loaded, a duty signal generation unit that generates a duty signal for the read wobble signal, and extracts the header information by comparing the generated duty signal It is also achieved by a playback device comprising a header information extraction unit that
[0033]
Preferably, the duty signal generator generates duty signals for an upper layer level that is a predetermined level greater than a center level of the read wobble signal and a lower layer level that is a predetermined level smaller than the center level.
[0034]
The header information extraction unit compares a duty ratio of the corresponding duty signal generated by the duty signal generation unit to generate binary data, and extracts the header information from the binary data generated by the comparator. It is effective to provide a demodulator for demodulation.
[0035]
On the other hand, in the apparatus for reproducing header information from a wobble signal, the object is to provide a single frequency wobble on which header information edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency is placed. A wobble signal reading unit that reads a signal, a level detection unit that detects a level of the read wobble signal at a predetermined phase, and a header information extraction unit that extracts header information by comparing the detected level with a predetermined reference value It is also achieved by a reproducing apparatus comprising:
[0036]
The header information extraction unit compares a detected level with a predetermined reference value to generate binary data, and a demodulator that demodulates the binary data generated by the comparator and extracts header information It is effective to provide
[0037]
On the other hand, in the apparatus for reproducing header information from a wobble signal, the object is to provide a single frequency wobble on which header information edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency is placed. A wobble signal reading unit that reads a signal, a differentiation unit that generates a differential signal with respect to the read wobble signal, and a header information extraction unit that extracts header information based on the generated differential signal It is also achieved by a playback device.
[0038]
The header information extraction unit includes an envelope detector that detects an upper envelope signal and a lower envelope signal of the differential signal, and the header information extraction unit includes an upper envelope signal and the lower envelope signal detected by the envelope detector. It is desirable to extract header information based on
[0039]
  The header information extraction unitUpper envelope signal and lower envelope signalAn arithmetic unit for obtaining the difference signal of the signal, a comparator for comparing the level of the difference signal obtained by the arithmetic unit with a predetermined reference value to generate binary data, and demodulating the generated binary data for header information It is even more desirable to include a demodulator that extracts.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0041]
FIG. 2 is a schematic view of an optical recording medium according to a preferred embodiment of the present invention.
[0042]
  Referring to FIG. 2, concentric circle (a) or spiral (b) tracks (groove tracks / land tracks) are formed on the optical disc according to the present embodiment. A wobble signal is recorded on the track. The wobble signal is one of means for recording an auxiliary clock signal for obtaining synchronization information during recording / reproduction. The wobble signal is provided in the recording / playback deviceTracking serverIt is used as an auxiliary clock signal that assists the system clock with a frequency in a band that does not affect the mechanism.
[0043]
3A and 3B are examples of forming the information track of FIG.
[0044]
As shown in the figure, when a groove track is recorded using a laser beam in the process of manufacturing an optical disk substrate, that is, a mastering process, a wobble signal is added to the right and left of the laser beam by adding a certain amount of offset. Recorded with shape changes on both walls. Referring to FIG. 3A, the wobble signal is recorded on both wall surfaces of the groove track, and in FIG. 3B, the wobble signal is recorded only on one side wall surface of the groove track. As described above, the wobble signal according to the present invention can be recorded on one side or both wall surfaces of the track as necessary.
[0045]
FIG. 4 is a block diagram of a wobble signal recording apparatus according to the present invention.
[0046]
Referring to FIG. 4, the wobble signal recording apparatus includes a wobble signal generation unit 4 and a recording unit 5. The wobble signal generator 4 generates a wobble signal according to the present invention. That is, a single-frequency wobble signal carrying header information is generated by edge-modulating the header information using the first signal and the second signal having different edge waveforms of the same frequency. Edge modulation will be described later.
[0047]
The recording unit 5 records the wobble signal generated by the wobble signal generation unit 4 on the optical recording medium 400. For this purpose, the recording unit 5 includes a pickup device provided with a laser diode capable of oscillating a laser beam.
[0048]
FIG. 5 shows the wobble signal recording apparatus of FIG.Reference exampleFIG.
[0049]
  Referring to FIG. 5, the wobble signal of the wobble signal recording device.Generator4 is a clock generator 41, a carrier signalGenerator42 and an edge modulator 43. The clock generator 41 generates a clock signal. Carrier signalGenerator42 generates the first and second signals based on the clock signal input from the clock generator 41. The first and second signals have the same frequency but have different edge waveforms. The edge modulation unit 43 receives the header information and generates a carrier signal based on the clock signal.GeneratorThe edge modulation is performed using the first and second signals of the carrier signal generated from. Here, the header information includes addressing information.
[0050]
  6 shows the carrier signal of FIG.Generator4 is a schematic diagram of first and second signals generated by 42. FIG.
[0051]
FIG. 6 (a) shows the present invention.Reference exampleThe 1st signal by is shown, (b) shows the 2nd signal. As shown, the first and second signals have the same frequency but different edge waveforms. In particular, the second signal is a sine wave. Therefore, when there is a pure wobble section in which header information is not included in the wobble signal, it is desirable that the pure wobble section is displayed as the second signal.
[0052]
FIG. 7 is a schematic diagram of a wobble signal edge-modulated by the first and second signals of FIG.
[0053]
Referring to FIG. 7, when the header information bit string whose header information is represented by digital data is “10101010”, the high level “1” corresponds to the first signal, and the low level “0” corresponds to the second signal. Is done. Ie bookReference exampleIt can be confirmed that the wobble signal according to is an edge-modulated signal based on the first and second signals.
[0054]
The present invention is based on the above configuration.Reference exampleThe wobble signal recording method according to the above will be described as follows.
[0055]
FIG. 8 shows the present invention.Reference example5 is a flowchart for explaining a wobble signal recording method according to FIG.
[0056]
Referring to FIG. 8, the clock generator 41 generates a clock signal (operation 801). Carrier signalGenerator42 generates first and second signals having the same frequency based on the clock signal but having different edge waveforms (step 802). The edge modulation unit 43 receives the header information and performs edge modulation using the first and second signals to generate a wobble signal having a single frequency (step 803). The recording unit 5 records the generated wobble signal on the optical disc 400 (step 804).
[0057]
FIG. 9 shows the wobble signal recording apparatus shown in FIG.1It is a detailed block diagram by embodiment.
[0058]
Referring to FIG. 9, the wobble signal generation unit 4 of the wobble signal recording apparatus includes a clock generation unit 91, a carrier signal generation unit 92, an edge modulation unit 93, a phase modulation unit 94, and a signal synthesis unit 95. The clock generator 91 generates a clock signal. The carrier signal generation unit 92 generates a carrier signal based on the clock signal input from the clock generation unit 91. The edge modulator 93 receives the first header information and performs edge modulation using the carrier signal based on the clock signal. The phase modulation unit 94 receives the second header information and performs phase modulation using the carrier signal based on the clock signal. The signal synthesizer 95 synthesizes the edge-modulated signal and the phase-modulated signal to generate a wobble signal according to the present embodiment. The recording unit 5 records the generated wobble signal on the optical disc 400. Here, the first and second header information includes addressing information. As described above, since the first and second header information is carried on one wobble signal, more header information can be recorded through the wobble signal. Furthermore, when at least a part of the first and second header information is composed of the same information, the density of the header information carried on the wobble signal is increased and the header information section is shortened. If the header information section of the wobble signal is shortened and the pure wobble section composed of a sine wave is extended, there is an advantage that the clock signal can be detected more stably.
[0059]
FIG. 10 is a schematic diagram of each signal generated from the wobble signal generation unit 4 of FIG.
[0060]
Referring to FIG. 10, (a) shows an edge modulation signal edge-modulated by the edge modulation unit 93 when the first header information is a digital signal and the bit string of the first header information is “101”. . (B) shows the phase modulation signal phase-modulated by the phase modulation unit 94 when the second header information bit string in which the second header information is displayed as a digital signal is “011”. (C) is a wobble signal obtained by synthesizing the edge modulation signal for the first header information bit string “101” and the phase modulation signal for the second header information bit string by the signal synthesis unit 95.
[0061]
Based on the configuration as described above,1The wobble signal recording method according to the embodiment will be described as follows.
[0062]
FIG. 11 shows the present invention.15 is a flowchart for explaining a wobble signal recording method according to an embodiment.
[0063]
Referring to FIG. 11, the clock generator 91 generates a clock signal (step 1101). The carrier signal generator 92 generates first and second signals having different edge waveforms with the same frequency based on the clock signal (step 1102). The edge modulator 93 receives the first header information and performs edge modulation using the first and second signals (step 1103). The phase modulator 94 receives the second header information and receives the firstas well asPhase modulation is performed using the second signal (step 1104). The signal synthesizer 95 synthesizes the edge modulation signal (a) and the phase modulation signal (b) to generate a single frequency wobble signal (c) according to the present embodiment (step 1105). The recording unit 5 records the generated wobble signal on the optical disc 400 (step 1106).
[0064]
12A is a diagram for explaining another example of a wobble signal according to the present invention. B FIG. 10 is a diagram for explaining still another example of the wobble signal according to the reference example.
[0065]
Referring to FIG. 12A, (a) illustrates an edge modulation signal obtained by edge-modulating a bit string of first header information, and (b) illustrates phase modulation in which a bit string of second header information is phase-modulated. A signal is illustrated, and (c) illustrates a modulation signal obtained by amplitude-modulating the bit string of the third header information. The modulation signal in (c) is highlevel“1” and low level “0” are displayed as sine waves having the same waveform and frequency, but highlevelA part of “1” has a difference in which the amplitude is zero. That is, the number of repetitions of the one-cycle waveform between “1” and “0” is different. (D) shows the wobble signal in which the edge modulation signal (a), the phase modulation signal (b), and the modulation signal (c) are combined. As described above, since the first, second and third header information are carried on one wobble signal, more header information can be recorded through the wobble signal. As in the case of FIG. 10, when at least part of the first, second, or third header information is the same, the header information section of the wobble signal can be reduced.
[0066]
Show other reference examplesReferring to FIG. 12B, FIG. 12A shows an edge modulation signal in which the bit string of the first header information is edge-modulated, and FIG. 12B shows a modulation signal in which the bit string of the second header information is amplitude-modulated. Is shown. (C) shows a wobble signal in which the edge modulation signal (a) and the amplitude modulation signal (b) are combined. Similarly, since the first and second header information is carried on one wobble signal, more header information can be recorded through the wobble signal. Furthermore, as in the case of FIG. 10, when at least a part of the first and second header information is the same, the header information section of the wobble signal can be shortened.
[0067]
FIG. 13 is an example of the addressing information {PID (Physical Identification Data) structure} of the header information section in which the wobble signal according to the present invention is recorded.
[0068]
Referring to FIG. 13, the optical disc according to the present embodiment has header information composed of four header information fields in one ECC (Error Correction Code) block (implemented from 64 KB or 32 KB in the present embodiment). The loaded wobble signal is recorded. Each header information field may be provided with synchronization data for detecting the identification character ID, a PID storing addressing information for each sector, and an IED (ID Error Detection) storing error detection information of the identification character ID.
[0069]
FIG. 14 is a block diagram of a wobble signal detection apparatus according to the first embodiment of the present invention.
[0070]
Referring to FIG. 14, the wobble signal detection apparatus includes a wobble signal reading unit 11, a duty signal generation unit 12, and a header information extraction unit 13.
[0071]
The wobble signal reading unit 11 reads a wobble signal from the optical recording medium 1400. The duty signal generation unit 12 generates a duty signal for the read wobble signal. More specifically, the duty signal generation unit 12 according to the present embodiment generates a duty signal for an upper layer level that is a predetermined level greater than the center level of the read wobble signal, and is lower than the center level of the read wobble signal by a predetermined level. Generate a duty signal for the lower level. The header information extraction unit 13 includes a comparator 131 and a demodulator 132 to compare the duty signal and extract header information. The comparator 131 compares the duty ratios of the corresponding duty signals generated by the duty signal generator 12 to generate binary data, and the demodulator 132 demodulates header information from the binary data generated by the comparator 131. . Here, the demodulation method of the demodulator 132 is determined by the encoding method of the header information. For example, if the header information is bi-phase encoded and then edge-modulated and loaded on the wobble signal according to the present invention, the demodulator 132 extracts the header information through bi-phase decoding.
[0072]
FIG. 15 is a reference diagram for explaining a duty signal generation process of the duty signal generation unit 12 of FIG.
[0073]
Referring to FIG. 15, (a) is a schematic diagram of a wobble signal composed of a first signal used for edge modulation, and (b) is a wobble composed of a second signal used for edge modulation. It is the schematic of a signal. The duty signal generation unit 12 is lower than the center levels C1 and C2 and the center levels C1 and C2 of the read wobble signals (a) and (b) by a predetermined level that is higher than the upper layers U1 and U2 and the center levels C1 and C2. Duty signals are generated at lower level L1 and L2. (C) shows duty signals c1, u1, l1 generated based on the first signal, and (d) shows duty signals c2, u2, l2 generated based on the second signal. Is shown. As shown, the duty ratio of the duty signal u1 is greater than the duty ratio of the duty signal u2, and the duty ratio of the duty signal l1 is smaller than the duty ratio of the duty signal l2. As described above, the duty signals u1 and l1 generated based on the first signal are different from the duty signals u2 and l2 generated based on the second signal. Binary data can be detected. Here, it is desirable to determine the level for detecting the duty signal to an appropriate value by experiment.
[0074]
The header information extraction method according to the first embodiment of the present invention will be described based on the above configuration.
[0075]
FIG. 16 is a flowchart for explaining the header information extraction method according to this embodiment.
[0076]
Referring to FIG. 16, the wobble signal reading unit 11 reads a wobble signal from the optical recording medium 1400 (step 1601).
[0077]
The duty signal generator 12 generates a duty signal for a predetermined level of the read wobble signal (step 1602). The comparator 131 detects the duty ratio of the generated duty signal and detects binary data based on the detected duty ratio (step 1603). The demodulator 132 demodulates the header information from the detected binary data (step 1604).
[0078]
FIG. 17 is a block diagram of a header information detection apparatus according to the second embodiment of the present invention.
[0079]
Referring to FIG. 17, the header information detection apparatus includes a wobble signal reading unit 16, a level detection unit 17, and a header information extraction unit 18.
[0080]
The wobble signal reading unit 16 reads a wobble signal from the optical recording medium 1700. The level detection unit 17 detects the level of the read wobble signal. More specifically, the level detection unit 17 according to the present embodiment detects the level at a time point preceding or delayed by a predetermined time centering on a time point when the amplitude of the read wobble signal is zero. The header information extraction unit 18 includes a comparator 181 and a demodulator 182 for comparing the detected levels and extracting header information. The comparator 181 compares the levels detected by the level detector 17 to generate binary data, and the demodulator 182 demodulates header information from the binary data generated by the comparator 181. Similarly, the demodulation method of the demodulator 182 is determined by the encoding method of the header information. For example, if the header information is bi-phase encoded and then edge-modulated according to the present invention and loaded on the wobble signal, the demodulator 182 extracts the header information through bi-phase decoding.
[0081]
FIG. 18 is a reference diagram for explaining a level detection method of the level detection unit 17 of FIG.
[0082]
Referring to FIG. 18, the level detection unit 17 detects a level at a time point preceding or delayed by a predetermined time centering on a time point when the amplitude of the read wobble signal is zero. As shown in the figure, a predetermined time point -t of the first signal having a trapezoidal waveform.₀, T₀It can be seen that the level magnitude at b is b, and the level magnitude of the second signal of the sine wave is a (a <b). Therefore, the predetermined time point -t₀, T₀After directly comparing the levels at or determining an appropriate reference value greater than a and less than b, binary data can be generated by comparing the determined reference value with the detected level.
[0083]
The header information extraction method according to the second embodiment of the present invention will be described based on the above configuration.
[0084]
FIG. 19 is a flowchart for explaining the header information extraction method according to this embodiment.
[0085]
Referring to FIG. 19, the wobble signal reading unit 16 reads a wobble signal from the optical recording medium 1700 (step 1901).
[0086]
The level detector 17 detects the level at a predetermined time point of the read wobble signal (step 1902). The comparator 181 compares the detected level with a predetermined reference value and detects binary data based on the comparison result (step 1903). The demodulator 182 demodulates the header information from the detected binary data (step 1904).
[0087]
FIG. 20 is a block diagram of a header information extraction apparatus according to the third embodiment of the present invention.
[0088]
Referring to FIG. 20, the header information extraction device includes a wobble signal reading unit 19, a differentiation unit 20, and a header information extraction unit 21.
[0089]
The wobble signal reading unit 19 reads a wobble signal from the optical recording medium 2000. The differentiating unit 20 generates a differential signal for the read wobble signal. The header information extraction unit 21 includes an envelope detector 211, a calculator 212, and a demodulator 214. The envelope detector 211 detects the upper envelope signal and the lower envelope signal of the differential signal from the differentiating unit 20. The calculator 212 subtracts the lower envelope signal from the upper envelope signal to obtain a difference signal. The comparator 213 generates binary data by comparing the level of the difference signal obtained by the calculator 212 with a predetermined reference value. The demodulator 214 demodulates the generated binary data and extracts header information. Similarly, the demodulation scheme of the demodulator 214 is determined by the header information encoding scheme. For example, if the header information is subjected to bi-phase encoding and then edge-modulated according to the present invention and carried on a wobble signal, the demodulator 214 extracts the header information through bi-phase decoding.
[0090]
FIG. 21 is a reference diagram for explaining each signal output from the header information extraction apparatus of FIG.
[0091]
Referring to FIG. 21, (a) shows the edge modulation wobble signal read by the wobble signal reading unit 19, and (b) shows the differential signal obtained by the differentiation unit 20 with respect to (a). . (C) shows an upper envelope signal and a lower envelope signal detected by the envelope detector 211 with respect to (b), and (d) shows a difference signal obtained by subtracting the lower envelope signal from the upper envelope signal of (c). Show. If the difference signal is compared with the wobble signal of (a), it can be seen that binary data carried on the wobble signal can be extracted from the difference signal.
[0092]
The header information extraction method according to the third embodiment of the present invention will be described based on the above configuration.
[0093]
FIG. 22 is a flowchart for explaining the header information extraction method.
[0094]
Referring to FIG. 22, the wobble signal reading unit 19 reads the wobble signal (a) from the optical disc 2000 (step 2201). The differentiating unit 20 generates a differential signal (b) for the read wobble signal (step 2202). The envelope detector 211 detects an envelope signal for the generated differential signal (step 2203). The header information detection unit 21 performs a predetermined calculation on the detected envelope signal, and extracts header information from the signal obtained as a result of the calculation (step 2204).
[0095]
FIG. 23 is a flowchart for explaining an example of the steps 2203 and 2204 in FIG.
[0096]
Referring to FIG. 23, in step 2203, the envelope detector 211 detects an upper envelope signal of the generated differential signal (step 2301) and detects a lower envelope signal (step 2302).
[0097]
The arithmetic unit 212 detects a difference signal between the upper envelope signal and the lower envelope signal (step 2303), and then compares the level of the obtained difference signal with a predetermined reference value to generate binary data (step 2304). . The demodulator 214 demodulates the generated binary data and extracts header information (step 2305). Here, the demodulation method employed in the demodulator 214 depends on the modulation method employed during recording.
[0098]
【The invention's effect】
As described above, according to the present invention, by recording the wobble signal generated by modulating the header information using the carrier signal having the same frequency, the header information can be extracted from the wobble signal and a more stable clock can be extracted. The signal can be extracted. In addition, the header information recording density can be increased by placing header information in the same section of the wobble signal.
[Brief description of the drawings]
FIG. 1 is a schematic view of a conventional optical disc.
FIG. 2 is a schematic view of an optical recording medium according to a preferred embodiment of the present invention.
FIG. 3A is an example of forming the information track of FIG.
3B is an example of forming the information track of FIG.
FIG. 4 is a block diagram of a wobble signal recording apparatus according to the present invention.
5 is a diagram of the wobble signal recording device of FIG.Reference exampleFIG.
6 is a schematic diagram of first and second signals generated by the carrier signal generation unit of FIG. 5;
7 is a schematic diagram of a wobble signal edge-modulated by the first and second signals of FIG.
[Fig. 8] of the present inventionReference example5 is a flowchart for explaining a wobble signal recording method according to FIG.
9 is a diagram of the wobble signal recording device of FIG.1It is a detailed block diagram by embodiment.
10 is a schematic diagram of each signal generated from the wobble signal generation unit of FIG. 9;
FIG. 11 shows the first of the present invention.15 is a flowchart for explaining a wobble signal recording method according to an embodiment.
FIG. 12A is a diagram for explaining another example of a wobble signal according to the present invention;FigureIt is.
FIG. 12BIt is a figure explaining the other example of the wobble signal by a reference example.
FIG. 13 is an example of addressing information in a header information section in which a wobble signal according to the present invention is recorded.
FIG. 14 is a block diagram of a wobble signal detection apparatus according to a first embodiment of the present invention.
15 is a reference diagram for explaining a duty signal generation process of the duty signal generation unit of FIG. 14;
FIG. 16 is a flowchart for explaining a header information extraction method according to the present embodiment;
FIG. 17 is a block diagram of a header information detection apparatus according to a second embodiment of the present invention.
18 is a reference diagram for explaining a level detection method of the level detection unit of FIG. 17;
FIG. 19 is a flowchart for explaining a header information extraction method according to the present embodiment;
FIG. 20 is a block diagram of a header information extraction apparatus according to a third embodiment of the present invention.
FIG. 21 is a reference diagram for explaining each signal output from the header information extraction device of FIG. 20;
FIG. 22 is a flowchart for explaining a header information extraction method;
23 is a flowchart for explaining an example of an envelope signal detection stage and a header information extraction stage in FIG. 22;
[Explanation of symbols]
4 Wobble signal generator
5 Recording section
11, 16, 19 Wobble signal readout section
12 Duty signal generator
13, 18, 21 Header information extraction unit
17 Level detector
20 Differentiation part
41, 91 clock generator
42,92 Carrier signal generator
43, 93 Edge modulator
94 Phase modulator
95 Signal synthesis unit
131,181,213 comparator
132,182,214 Demodulator
211 Envelope detector
212 Calculator
400, 1400, 1700, 2000 Optical recording medium

Claims (19)

In optical recording media,
A wobble track on which user data is recorded, wherein the wobble signal recorded on the wobble track is edged with first header information using a first signal and a second signal having different edge waveforms of the same frequency. A single frequency signal that is modulated and loaded,
2. The optical recording medium according to claim 1, wherein the second header information is phase-modulated and loaded on at least a part of the edge-modulated section of the wobble signal.   2. The optical recording medium according to claim 1, wherein the third header information is amplitude-modulated and mounted on at least a part of the edge-modulated section of the wobble signal.   The optical recording medium according to claim 1, wherein the first header information includes addressing information. In an apparatus for recording a wobble signal on an optical recording medium,
Generates a single frequency wobble signal in which the first header information subjected to edge modulation and the second header information subjected to phase modulation are loaded based on the first signal and the second signal having different edge waveforms of the same frequency. A wobble signal generator to
A recording apparatus comprising: a recording unit that records the wobble signal generated by the wobble signal generation unit on the optical recording medium. The wobble signal generation unit includes a carrier signal generation unit that generates the first and second signals;
An edge modulation unit for edge-modulating the first header information using the first signal and the second signal;
A phase modulation unit for phase-modulating the second header information using the first signal or the second signal;
And a signal combining unit configured to combine the edge modulation signal output from the edge modulation unit and the phase modulation signal output from the phase modulation unit to output the single frequency wobble signal. 4. The recording device according to 4. In a method for recording a wobble signal on an optical recording medium,
(A) generating a first signal and a second signal having different edge waveforms of the same frequency;
(B) generating a single frequency wobble signal carrying the first header information edge-modulated and the second header information phase-modulated using the generated first signal and the second signal;
(C) recording the generated single frequency wobble signal. In step (b),
(B1) generating a clock signal;
(B2) edge-modulating the first header information with the generated clock signal using the first signal and the second signal;
(B3) phase-modulating the second header information with the generated clock signal using the first signal and the second signal;
7. The method of claim 6, further comprising: (b4) combining the single frequency wobble signal by superimposing the edge modulation signal of step (b2) and the phase modulation signal of step (b3). Recording method. In a method for reproducing header information from a wobble signal recorded on an optical recording medium,
(A) reading a single frequency wobble signal carrying header information that has been edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency;
(B1) generating a duty signal for an upper layer level that is a predetermined level greater than the center level of the read wobble signal;
(B2) generating a duty signal for a lower level that is a predetermined level lower than the center level of the read wobble signal;
(C) A reproduction method comprising: comparing each duty signal generated in steps (b1) and (b2) to extract header information. In step (c),
(C1) generating binary data by respectively comparing the duty ratios of the duty signals generated in the steps (b1) and (b2);
The reproduction method according to claim 8, further comprising: (c2) extracting the header information from the detected binary data. In a method for reproducing header information from a wobble signal recorded on an optical recording medium,
(A) reading a single frequency wobble signal carrying header information that has been edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency;
(B) detecting a level at a predetermined phase of the read wobble signal;
And (c) extracting the header information by comparing the detected level with a predetermined reference value. In step (c),
(C1) comparing the detected level with a predetermined reference value to generate binary data;
The reproduction method according to claim 10, further comprising: (c2) demodulating the generated binary data to extract header information. In a method for reproducing header information from a wobble signal recorded on an optical recording medium,
(A) reading a single frequency wobble signal carrying header information that has been edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency;
(B) generating a differential signal for the read wobble signal;
(C) extracting header information based on the generated differential signal,
In step (c),
(C1) detecting an upper envelope signal of the differential signal;
(C2) detecting a lower envelope signal of the differential signal;
(C3) A step of extracting header information based on the upper envelope signal and the lower envelope signal. The step (c3) includes
(C31) obtaining a difference signal between the upper envelope signal and the lower envelope signal ;
(C32) comparing the level of the obtained difference signal with a predetermined reference value to generate binary data;
The reproduction method according to claim 12, further comprising: (c33) demodulating the generated binary data to extract header information. In an apparatus for reproducing header information from a wobble signal recorded on an optical recording medium,
A wobble signal reading unit that reads a single frequency wobble signal on which header information that has been edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency is mounted;
A duty signal generator for generating a duty signal for an upper layer level that is a predetermined level larger than a center level of the read wobble signal and a lower layer level that is smaller than a predetermined level;
A playback apparatus comprising: a header information extraction unit that extracts header information by comparing each generated duty signal.   The header information extraction unit compares the duty ratio of the corresponding duty signal generated by the duty signal generation unit to generate binary data, and the header information from the binary data generated by the comparator The reproduction apparatus according to claim 14, further comprising a demodulator that demodulates the signal. In an apparatus for reproducing header information from a wobble signal recorded on an optical recording medium,
A wobble signal reading unit that reads a single frequency wobble signal on which header information that has been edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency is mounted;
A level detector for detecting the level of the read wobble signal at a predetermined phase;
A playback apparatus comprising: a header information extraction unit that extracts header information by comparing a detected level with a predetermined reference value. The header information extraction unit
A comparator that compares the detected level with a predetermined reference value to generate binary data;
The reproduction apparatus according to claim 16, further comprising: a demodulator that demodulates binary data generated by the comparator and extracts header information. In an apparatus for reproducing header information from a wobble signal recorded on an optical recording medium,
A wobble signal reading unit that reads a single frequency wobble signal on which header information that has been edge-modulated using a first signal and a second signal having different edge waveforms of the same frequency is mounted;
A differentiating unit for generating a differential signal with respect to the read wobble signal;
A header information extraction unit that extracts header information based on the generated differential signal;
The header information extraction unit includes an envelope detector that detects an upper envelope signal and a lower envelope signal of the differential signal,
The playback apparatus according to claim 1, wherein the header information extraction unit extracts header information based on the upper envelope signal and the lower envelope signal detected by the envelope detector. The header information extraction unit
An arithmetic unit for obtaining a difference signal between the upper envelope signal and the lower envelope signal ;
A comparator that generates binary data by comparing the level of the difference signal obtained by the computing unit with a predetermined reference value;
19. The reproducing apparatus according to claim 18, further comprising a demodulator that demodulates the generated binary data and extracts header information.

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